665263620 has 72 divisors (see below), whose sum is σ = 2306251584. Its totient is φ = 152059968.

The previous prime is 665263609. The next prime is 665263633. The reversal of 665263620 is 26362566.

665263620 is a `hidden beast` number, since 6 + 6 + 5 + 26 + 3 + 620 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 262734 + ... + 265253.

It is an arithmetic number, because the mean of its divisors is an integer number (32031272).

Almost surely, 2^665263620 is an apocalyptic number.

665263620 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

665263620 is an abundant number, since it is smaller than the sum of its proper divisors (1640987964).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

665263620 is a wasteful number, since it uses less digits than its factorization.

665263620 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 528009 (or 528004 counting only the distinct ones).

The product of its (nonzero) digits is 77760, while the sum is 36.

The square root of 665263620 is about 25792.7047825543. The cubic root of 665263620 is about 872.9671972339.

The spelling of 665263620 in words is "six hundred sixty-five million, two hundred sixty-three thousand, six hundred twenty".